Signalling drift indicator with fluid by-pass



Sept. 16, 1969 l R,1 L, ALDER 3,466,754

SIGNALLING DRIFT INDICATOR WITH FLUID BY-PASS Filed March 22. 1967 NAW iaz /3 5 i`l INVNTOR. 5 05527 Au United States Patent O M 3,466,754SIGNALLING DRIFT INDICATOR WITH FLUID BY-PASS Robert L. Alder, Pasadena,Calif., assigner to Byron Jackson, Inc., Long Beach, Calif., acorporation of Delaware Filed Mar. 22, 1967, Ser. No. 625,084 Int. Cl.E21b 47/02 U.S. Cl. 33-205 7 Claims ABSTRACT F THE DSCLSURE A signallingdrift indicator of the type in which a knob moves through pulse rings toproduce pressure signals in a stream of drilling fluid indicative of thedisposition of the drill String and in which a by-pass for drilling uid,open only While signals are being produced, is provided.

The present invention relates to signalling drift indicators for use inthe drilling of bore holes or wells through or into the earth, and moreparticularly to improvements whereby uid is allowed to bypass thedrilling bit while the drift indicator is being operated to generatesignals in the drilling iiuid.

Signalling drift indicators of the general type here involved aredisclosed in U.S. Patents Nos. 2,435,934, issued Sept. 10, 1948, to F.M. Varney et al., and 2,7 62,- 132, issued Feb. l1, 1956, to I. A.Varney, as Well as in U.S. Patent No. 3,176,407, issued Apr. 6, 1965, toR. L. Alder et al. In these prior inventions pressure pulses or signalsare produced in the stream of drilling kfluid adjacent the drill bit andare detectable at the surface of the earth as an indication of the angleof the lower end of the drill string from vertical, such signals beinggenerated in a number which is either directly or inversely related tothe angularity of the drill string adjacent the bit.

Such devices are of substantial benet to the driller in determiningwhether he is maintaining desired or proper control of the weightapplied to the bit with resultant control of the progression of the holerelative to a selected angle or relative to vertical, as well as beingof substantial benefit to the driller in determining relative bitefliciency, i.e., whether the bit should be changed to enable increasedpenetration rate at a given depth in the light of the time required tomake a round trip of the drill pipe to change bits, all as is now wellknown in the art.

Heretofore, in the use of devices of the general type described above,it has been the practice to cause operation of the signal producingmeans in response to the cessation and resumption of the circulation ofdrilling uid. In such devices, cessation of drilling uid circulationallows the upward travel of a flow pressure responsive head or knobthrough a series of restrictions, and resumption of drilling fluidcirculation causes the downward travel of the knob through a number ofthe restrictions related to the angle of the drill string, or moreprecisely the drill collar sub, in which the knob is disposed. Means areincluded in such devices which are operative in response to gravity tolimit upward travel of the knob in a particular relation, direct orinverse, to the angle of the sub. However, under some circumstances,restriction in the iiow of drilling fluid may interfere with operation'of the drift indicator signal production. For example, if the bit hassmall orices through which the drilling uid is flowing or when the bitorifices are plugged up, the flow rate through the signal 3,466,754Patented Sept. 16, 1969 producing means may be slow or may be erratic,resulting in loss of signal amplitude or erratic spacing of the signalsdue to the fact that the knob may pass too slowly or erratically throughthe restrictions.

Accordingly, an object of the present invention is to provide asignalling producing apparatus by which signals or pressure pulses willbe generated in the stream of drilling fluid as an indication of thedisposition of the lower end of the drill string, and which, as animprovement, includes means whereby at least a portion of the drillingfluid bypasses the bit so as to assure adequate and constant ow of fluidfor the purpose of causing the knob to move properly through therestrictions, whereby signals will be produced of sufficient amplitudeand regularity as to be readily detectable at the earths surface eventhough the bit orifices may be plugged or of small size.

More specifically, an object is to provide by-pass valve means in asignalling drift indicator having a knob movable through pulse rings orrestrictions, said Valve means being closed during drilling operationsso that the full volume of drilling fluid -will pass through the bitorifices to flush cuttings upwardly in the annulus outside the drillstring, and said valve means being open to allow the drilling uid, or atleast a substantial portion thereof, to pass into the annulus above thebit without owing through the bit.

Other objects and advantages of the invention will be hereinafterdescribed or will become apparent to those skilled in the art and thenovel features of the invention will be defined in the appended claims.

In the drawing:

FIG. 1 is a view in longitudinal section, with certain of the partsshown in elevation, illustrating a signalling `drift indicator made inaccordance with the invention,

with the by-pass valve closed;

FIG. 2 is a transverse sectional view as taken on the line 2-2 of FIG.l; and

FIG. 3 is a fragmentary view showing the by-pass valve of FIG. l in anopen position.

Like reference characters in the drawing and in the followingdescription designate corresponding parts.

Referring first to FIG. 1, there is shown an instrument I made inaccordance with the invention and disposed in a drill collar sub C,having a body 1, pin end 2, and a box end 3 for threaded connection inthe drill string. Pin end 2 is formed on a cap 4 which is suitablyremovably connected to the body 1 as by a thread (not shown) whereby theinstrument may be installed in the body 1. This instrument includes apulse or signal prducing section P and a shaft and pendulum section S.The latter section S includes a housing 5 at the lower end of which is abottom support 6 in the form of a spider providing ow passages 7, thisbottom support seating on a shoulder 8 at the bottom of drill collarbody 1. Housing S of section S is connected by a spider 9 having flowpassages 10, to the pulse section P.

Pulse section P includes a pulse ring fitting 12 which is a tubularmember welded at 13 to, or otherwise made a part of, the spider 9. Thisfitting 12 lits within drill collar body 1 and has an upper ange 14which seats on a shoulder 15. Means are provided to form a seal betweenthe fitting 12 and drill collar body 1, and illustratively such meansincludes a resilient seal ring carried by fitting 12 and engaged inbody 1. Within the fitting 12 is a vertically spaced series of pulserings 1-6 providing successive restrictions and enlarged liow areaswhereby to produce pressure pulses in the stream of drilling uid as aknob 17 passes downwardly therethrough in a manner hereinafter to bedescribed.

The knob 17 is supported at the upper end of a shaft 18 which extendsvertically through a seal 19 carried at the upper end of shaft section Sof the instrument I. Within the instrument housing 5, a main spring 20acts on a ange 21 of shaft 18 to normally bias the shaft and knobupwardly when the circulation of drilling fluid is interrupted. Meansare provided within the housing for limiting upward movement of shaft 18a distance related to the angle of drift of the drill collar C and thewell from vertical, so that upward movement of knob 17 will becorrespondingly limited. As seen in FIG. 1, this means comprises apendulum 22 pivotally supported beneath shaft 18 by bail means 23 andhaving a head 24 providing a shoulder which is selectively engageablewith one of a plurality of axially spaced annular stops 25 ofprogressively diminishing diameter. It will be recognized that theangular disposition of the drill collar C relative to the pendulum 22,which, being gravity responsive will depend vertically from its pivot,will determine which stop 25 will be engaged by pendulum head 24, andthat, while in the structure shown the permitted upward travel of thependulum and the shaft is inversely related to the angular dispositionof the body, i.e., the greater the angle the less the travel, theassembly may include a coding system for enabling a direct relationshipbetween angle and extent of shaft travel, as disclosed in the aforesaidU.S. Patent No. 3,176,407.

In either event, downward movement of the knob 17 from the positionshown in FIG. 3 to the original position shown in FIG. l responsive toflow of drilling liuid through the pulse rings 16 will cause theproduction of pressure signals in the fluid stream which are detectableat the earths surface for purposes of indicating the angle of the drillcollar C. In order that the pulses will be of sufiicient duration as tobe easily discriminated from normal pressure variations in the fluidstream, a clean body of oil in the pendulum section S is displacedthrough an orifice assembly including a number of orifice discs 26,which are disposed in a passage 27 in a combined disc support andpendulum seat 28 which is mounted in the section 5 between rings 29. Aby-pass passage 30 and a downwardly closing check valve 31 are providedin the support 28 for allowing relative freedom of upward movement ofinstrument fluid in section S through support 28 during upward movementof shaft 17.

This clean oil or instrument fluid is retained in the body 5 of sectionS by means of seal ring 19 at the upper end of body 5 and by a pressureequalizing divider below the support 28. The divider in the illustrativeembodiment is in the form of a diaphragm 32, but a free piston may alsobe employed.

The instrument as thus far described is substantially conventional, andin accordance with the objectives of the invention is provided withvalve means which is closed when the knob 17 is down, as shown in FIG.l, and which is open when the knob moves upwardly, so as to allow fluidto bypass the instrument during downward movement of the knob.

This valve means in the illustrative embodiment includes in the lowerend of the pulse ring fitting a number of circumferentially spacedinward projections 33 having arcuate inner walls 34, cooperative with anannular surface 35 on knob 17, and radial ports 36 which extend throughthe projections 33 and outwardly through drill collar body 1. With sucha construction, the knob 17 effectively is a valve for closing the ports36 when the knob is down, as seen in FIG. 1, and for opening the ports36 when the knob moves upwardly.

Thus, in operation, so long as the circulation of drilling uiddownwardly through drill collar C is maintained, the knob 17 will remaindown and the entire volume of iiuid will flow downwardly through theusual bit orifices. However, when circulation is interrupted to allowthe addition of a further length of drill pipe or to enable, at anytime, the taking of a deviation reading, the knob will be moved upwardlyby mainspring 15, limited by engagement of pendulum head 24 with one ofthe stops 25. Thereafter, upon resumption of circulation of the drillingtiuid, the knob 17 will be forced downwardly by the drilling fluid,causing the generation of a pressure pulse or signal at each pulse ringrestriction.

Since the ports 36 are open when the knob 17 is up, a portion, at least,of the fluid being pumped down the drill string will bypass theinstrument below the ports and will flow directly into the annulusoutside the drill collar C. Therefore, if the usual bit orifices aresmall or are plugged so as to impede downward tiow of the drillingfluid, sufiicient fluid will bypass through ports 36 so as to enableadequate fluid velocity through the pulse ring fitting to cause welldefined pressure pulses at the rings 16 as knob 17 passes therethrough.After the pulses have been generated and the knob 17 reaches the downposition the cooperative valve surfaces 34 on projections 33 and 35 onknob 17 will close ports 36, so that again the entire volume ofcirculating drilling fluid will pass through the bit orifices to assureelicient removal of cuttings.

While the specific details of an illustrative embodiment of theinvention have been herein shown and described, changes and alterationsmay be resorted to without departing from the spirit of the invention.

I claim:

1. In a signalling apparatus adapted to be installed in a well drillingstring for producing pressure signals in a stream of well drilling fluidindicative of the angular disposition of the drilling string, saidapparatus comprising: a tubular elongated body adapted to be installedin the drilling string, an instrument in said body having means forproducing pressure pulses in the drilling fluid stream followinginterruption of the flow of fluid through said body and responsive toresumption of liow of fluid through said body, and bypass means openablefor allowing the fiow of fiuid laterally from said body to the exteriorthereof during the production of said pulses and closeable following theproduction of said pulses for causing the entire fluid stream to flow`axially through said body.

2. Signalling apparatus as defined in claim 1, wherein said instrumentincludes a movable member having a fluid flow responsive surface forholding the same in a first position during liow of fluid through saidbody, means for biasing said member to a second position uponinterruption of the liow of fluid through said body, and said bypassmeans includes port means leading to the exterior of said body, andvalve surfaces for closing said port means when said member is in saidrst position.

3. Signalling apparatus as defined in claim 2, wherein said valvesurfaces include surfaces on said movable member for closing said portmeans.

4. In a signalling apparatus adapted to `be installed in a well drillingstring for producing pressure signals in a stream of well drilling uidindicative of the angular disposition of the drilling string, saidapparatus comprising: a tubular body adapted to be installed in thedrilling string, a housing in said body, a member projecting from saidhousing and movable between a first position and a second positiondetermined by the disposition of said body relative to vertical, saidmember having a surface responsive to flow of drilling liuid to movesaid member to and hold said member in said first position, means insaid housing for moving said member to said second position uponinterruption of the flow of drilling fluid, means cooperative with saidmember for producing pressure pulses in the stream of drilling fluidupon resumption of the flow of drilling iiuid vand movement of saidmember toward said first position, and bypass means closeable when saidmember is in said first position and openable when said member is spacedfrom said first position to allow drilling lipid to bypass said body.

6. Signalling .apparatus as defined in claim 4, wherein 5 said bypassmeans includes a plurality of angularly spaced projections in said bodythrough which said member eX- tends, a port leading from the exterior ofsaid body through a projection into said body, and Valve meansengageable with said projection having said port.

7. Signalling apparatus as dened in claim 4, wherein said means formoving said member to said second position includes a spring in saidhousing and pendulum and body relative to vertical to limit movement ofsaid member under the inuence of said spring.

References Cited UNITED STATES PATENTS 3,176,407 4/1965 Alder et al.

2,762,132 9/ 1956 Varney.

2,435,934 9/1948 Varney et al.

1,905,299 4/1933 McLaughlin et al 33-205 10 LEONARD FORMAN, PrimaryExaminer F. I. DAMBROSIO, Assistant Examiner U.S. Cl. X.R.

spaced stop means responsive to the disposition of said 15 175-45

